Vibratory conveyors have been used for some time and take various forms or configurations depending upon the materials or articles to be conveyed and the system within which the conveyance is to be employed. There are many types of straight-line vibrating conveyors which often are inclined to convey materials or articles generally in a horizontal direction but slightly up an inclined ramp. Circular conveyors also are known for lifting materials or articles and frequently use a spiral configured conveying ramp. With circular conveyors, vibrating motion causes the articles to move continuously in a circle while moving upwardly along the spiral ramp. Therefore, the motion transmitted or imparted to the conveyor must be both vertical and twisting in a horizontal plane. This is sometimes called a helical reciprocating motion. Such vibratory conveyors are used because of their versatility in operating with less energy costs and can handle quite a variety of materials or articles, ranging from machinery parts to very fragile articles. One such device is shown in my earlier issued U.S. Pat. No. 3,789,977 where the spiral ramp has an outer vertical shoulder for retaining the articles or materials on the ramp for elevating same.
Other such vertical lift devices were disclosed in U.S. Pat. Nos. 2,658,286 and 3,053,380 to W. V. Spurlin, in U.S. Pat. No. 3,178,013 to Hubbard and U.S. Pat. No. 4,248,737 to Pellerin et al all of which show spiral ramps in tubes around tubes and/or with vertical shoulders for confining the articles or material to the ramp for vertical conveying.
Another form of vertical conveyor using a spiral ramp is shown in U.S. Pat. No. 3,171,538 to L. D. Hagenbook wherein the spiral ramp is in a tube or cylinder with an open center. The Hagenbook ramp and tube are rotatably driven about the vertical axis so as to screw the material up the ramp and outwardly against the inside of the tube by centrifugal forces.
One of the areas of continuous problems is in applications for conveying bulk materials with vertical, spiral lift-type conveyors. With the conveyance of individual articles, the spiral ramp often is simply cupped in a cross-direction and the articles can be vibratorily lifted along the spiral ramp without even having any confining means about the periphery of the ramp. However, in dealing with bulk materials, there often are limitations as to the height which the materials can be conveyed within reasonable parameters, such as the size of the ramp, the vibrating or orbiting motor drive, the method of feeding the lower end of the conveyor, and other components. Often, the vibratory drive means may be mounted intermediate the ends of the vertical conveyor, or plural drive means may be employed both at the bottom and the top of the conveyor in order to impart adequate helical reciprocating movement to the bulk materials. There appears to be an interrelationship between the vertical ramp construction, the method of feeding the bulk materials and confinement of the materials during vertical lift.
This invention is directed to solving the problems existent with current vertical conveyors and satisfying the need for a new and improved vertical mass flow conveyor particularly for bulk materials.